Pigment based inkjet inks have assumed a leading market position in desktop as well as wide-format inkjet printing since they provide outstanding light-and water-fastness. The technical requirements on pigmented inkjet inks are tremendously increased by faster printing speed and modern application fields such as commercial inkjet printing. The dispersibility of pigments is one of the key performances to enable the development of such high quality pigmented inkjet inks with tailored particle size distribution and highest optical densities. This technical study focuses on a series of surface oxidized carbon black pigments based on the same carbon black source. Prepared dispersions under the same conditions based on these grades show the strong influences of surface oxidation on carbon black pigments on the dispersibility and the different demand on dispersing additives. Finally, optical densities and long term stability testing of final inkjet inks based on these surface oxidized carbon black pigments were evaluated. The test study shows the advantage of surface oxidized carbon black pigments in regard to improved dispersibility, more economical dispersing processes and higher optical densities for aqueous inkjet ink systems.